Neutron multiplicity assay of impure materials using four different neutron counters

During an advanced IAEA inspector training course given at Los Alamos in November, 1997, the opportunity existed for an intercomparison study of various neutron detectors to quantify measurement performance using pure and impure plutonium oxide and mixed uranium-plutonium oxide (MOX) items. Because of the cost of counters designed specifically for multiplicity analysis, it was desired to explore the limits of other, less costly and less efficient detectors. This paper presents and intercompares neutron coincidence and multiplicity assay performance for five detectors, which vary widely in detection efficiency. Eight pure plutonium oxide and twelve impure plutonium oxide and MOX working standards were used in the study